In a cellular communications system, base stations are used to serve the devices of mobile user with data, voice and other services. Each base station has a limited range so that when a user moves to far away from a base station, the connection with that base station must be handed over or handed off to a different base station that is closer to the user. This allows the base stations and the user devices to use lower power. To provide the handovers, elaborate processes have been developed to transfer the connections.
Each base station is typically also connected to some upstream equipment that is, in turn, connected to the telephone network, the Internet and other data sources. This upstream equipment has high speed data paths to the base stations that it serves and is normally limited to some number of base stations. When the mobile user goes beyond this group of base stations, the connection can be lost or some more complicated set of data connections must be used.
In a broadband wireless network, such as a WiMAX or 3GPP LTE (Third Generation Partnership Project Long Term Evolution) network, each base station is coupled to a gateway and the gateways all are assigned to a particular cluster. When the mobile user moves to a base station that is outside the cluster or is not directly connected to the same gateway, then the data for the mobile user must be passed from one gateway to another to reach the user. In order to support many users moving around among many gateways, the connections between gateways must be built to carry a large amount of data traffic from the users. This can delay the data in reaching the user. In order to quickly transfer all the user data between gateways the gateways and their connection must are made more expensive.